Drawing-in power-hammer die.



O. LINDSTROM (KL-T. MAKELA.

DRAWING-IN POWER HAMMER DIE.

APPLICATION FILED DEC-29. 19H

Patented Jan. 7, 1919.

2 SHEETS-SHEET I.

INVENTORS:

0 LINDSTROM 84 T. MAKELA.

DRAWING-IN POWER HAMMER DIE.

APPLICATION FILED 02129. 1917.

. Patented Jan. 7, 1919.

2 SHEETS--SHEET 2.

Hi I

Ill

U'ITO IIINDSTROM AND 'IOIVO MAI (EDA, 01E INDIANAPOLIS, INDIANA,ASSIGNORS 01E ONE-THIRD 'IO JOHN HAMLIN, OI MUNCIE, INDIANA.

DRAWING-IN POWER-HAMMER DID.

Specification of Letters Patent.

Patented Jan. "3, IHIF.

Application filed. December $29, 1917. Serial No. 209,4t1.

Iower-Hammer Dies, of which the following is a specification, referencebeing had to the accompanying drawings and to the letters and figures ofreference marked thereon.

This invention relates to dies that are de signed to be used in a powerhammer for till shaping or reshaping sheet metal, the invention havingreference more particularly to dies whereby portions of a sheet or plateof metal may be drawn in or contracted, either to effect a reduction inwidth of the sheet or plate if finished so as to be flat, or to causecurvature of the sheet or plate when desired. 1

An object of the invention is to provide means whereby drawing-inoperations on sheet or plate metal may be expeditiously and eflicientlyperformed without necessitating the use of costly form dies. in a press,

more particularly when curved forms are required.

Another object is to provide improved means whereby sheet metal may beformed into curved shapes, whether regular or irregular curvature, andmore rapidly and elliciently than by the well known hand-ham meringprocess.

A further object is to provide simple and inexpensive dies which shallbe adapted to be used for producing various curved shapes of sheet metalby the hammering process and which shall be durable and economical 1nuse.

lWith the above-mentioned and other objects in view, the inventionconsists in a pair of novel hammer dies whereby portions of sheet metalmay be drawn in or structurally contracted and whereby also plates maybe formed into dish shape or into bowl shape or into various curvedshapes that may be desired. And the invention consists also further ofthe parts and combinations and arrangements of parts as hereinafterparticularly described and further defined in the accompanying claims.

Referring to the drawings, Figure 1 is a fragmentary front elevation ofa well-known type of power-hammer which for the pur pose of illustratingthe invention is provided with the improved dies; Fig. 2 is a sideelevation of Fig. 1; Fig. 3 is an elevation of one of the improved dies,that portion commonly used as the front portion being shown; Fig. a is aside elevation of the die shown in the preceding figure which preferablyis the lower one of the pair of dies; Fig. 5 is a plan of the face ofthe upper one of the pair of dies; Fig. 6 is a cen tral vertical sectionof the pair of dies on the line Vl-Vl[ on Fig. 2; Fig. 7 is a plan ofthe face of the lower one of the dies; Fig. 8 is a section of the upperone of the dies on the line VIII-VIII on Fig. 5; Fig. 9 is a sideelevation of the improved dies in operation in the power-hammer machinewhich 'is shown by broken lines; Fig. 10 is a front view of the dies asin operation in a hammer machine which is indicated by broken lines;Fig. 11 is a rear elevation of the improved dies as when working on asheet of metal; Fig. 12 is a central section of the dies as when workingon a sheet of metal; Fig. 18 is a top plan of a Plate which is partiallycurved and indicated as being upon. the bottom die; and, Fig. 1a is arear elevation of a pair of dies, the upper one being partially brokenaway, slightly modified to illustrate duplication of essential featuresthereof.

Similar reference characters on the different figures of the drawingsindicate like parts or elements hereinafter referred to in detail.

A power hammer with which the im proved dies are advantageously used forworking on metallic sheets of such thickness as is capable of beingshaped by the till ower and ca acit of such hammerin machine comprises asuitable upright column or support 1 whlch supports an arm 2 havmg ananvil 3 thereon, the latter being adapted to hold a bottom or lower die.

Above the arm a frame a is supported also by the column or support 1 andit has a guide head 5 thereon and rotatably supports a suitably drivenshaft 6 which has a head 7 thereon provided with a crank pin 8 to whicha pitman or connecting rod 9 is connected, the latter being secured to a'bow spring 10. A hammer body 11 is vertically guided by the head 5 andconnected with the bow spring by means of suitable links 12 and 13, thehammer body being adapted to tilt Itltl forced hard on to the metallicsheet.

hold a top or upper die opposite to the bottom or lower die.

Two improved dies 14 and 15 are provided for the purpose intended, thedie 14.- preferably being used as the bottom or lower die and is securedwith its face uppermost to the anvil 3, the companion die 15 being secured with its face undermost to the hammer body 11. The lower die lathas an approximately flat central face 16 upon the rear portion of whichis a projecting rib or ridge 17 that has a sloping top 18 whichgradually merges into the flat face 16. The rib is relatively broader atits base than at its top and it conveniently extends to the rear side ofthe die. The top of the die has a rounded edged portion 19 so thatconcave surfaces may be worked thereon. The face of the top die 15 hasan approximately flat central portion 20 in which is a groove or recess21 having a sloping bottom 22 that extends gradually from the face 20and progressively deeper into the body of the die to the rear sidethereof to receive the rib or ridge 17 without contact therewith, thegroove or recess bein sufficiently capacious to permit the rib to forcea portion of sheet metal therein without forcing the metal to the bottomof the groove when the metal is forced to the face 16 and the face 20 isThe face of the upper die has a rounded edge portion 23 so as to clearthe metallic sheet when being handled between the dies.

The dies may have more than one rib or groove, as will appear in Fig. 14in which a pair of dies 14 and 15 appear, the lower die having twoadditional ribs or ridges 2 1 and 25, the companion die havingadditional grooves 01 recesses 26 and 27 to receive the additional ribs.

As an illustration of the manner of using the improved dies, a sheet orplate of metal is placed upon the bottom die 14 with the portion 28 ofthe sheet that may be flat and so remain foremost or toward the operatorwho moves the sheet forward and rearward repeatedly, each forwardmovement being intermittent with each hammer stroke, so as to bring therearward end thereof over the rib or ridge 17, the hammer being stoppedwhile moving the sheet rearward; and, if the flat portion of the sheetbe forcibly drawn downward by hand the rearward portion of the sheet maybe formed with a curvature 29 on which a rib or crease 30 required inthe drawing-in process is formed. As the sheet or plate is progressivelydrawn forward it is first creased by the rib 17 forcing the metal of thesheet into the groove 21, the metal of the sides of the crease beingupset in the shallow portion of the groove, and the crease beingimmediately drawn onto the flat face 16 of the die on which the creaseis hammered flat, thus drawing in or contracting the metal by condensingthe molecular structure thereof so as to reduce the width of a portionof the sheet or plate. The sheet is repeatedly shifted laterally untildrawn in as may be desired and may be left in flat condition throughoutif kept in horizontal position on the die. In Fig. 11 the rear edge ofthe metal sheet is seen as being drawn in and curved, 31 indicating theforward portion of the sheet, and 32 the curved rearward edge portion onwhich a corrugation 33 is formed by the dies to be immediately drawnforward, the metal of the sides of the corrugation condensed and themetal flattened on the flat face .at the lower end of the rib 17. InFig. 12, 3 1 indicates the forward portion in position to be hammered onthe flat face of the die, 35 indicating the rearward portion of thesheet which is curved and formed with a corrugation 36 to beprogressively ondensed at its sides in the groove and brought to thefiat face 16 and hammered fiat thereon. In Fig. 13, 37 indicates theflat unchanged portion of the metallic sheet or plate and 38 a curvedport ion resulting from having been operated upon by the dies. In somecases the sheet or plate of suitable pattern is given a dished shape 39as appears in Fig. 10 by continuous shifting of the metal sheet in a.rotary direction and forward and backward upon the bottom die, repeatingthe operation oftener near the edge portion of the sheet or dish, and insuch case the middle portion of the completed dish or bowl may be leftflat or may be curved as well as the side portions thereof. In producingthe hemispherical dish the sheet is tilted on the lower die. The diesare particularly useful for shaping sheet metal, automobile bodies whenthey are required to have curved portions, or for drawing in andeliminating accidental indentations'in the metal, and especially when itis desired that each body have a distinctly original or special curveddesign different from all other bodies.

It will be apparent that after a corrugation or crease is formed themetal of the sides thereof stands up at an inclination, yet sufficientlyapproximating on edge arrangement to permit the hammer blows to condensethe molecular structure of the metal in one direction and thus reducethe height of the side, and therefore when the crease is flattened thewidth of the sheet is less than before the treatment; or, if the sheetis not flattened the metal comprising the rim or side portion of thedisk or bowl is drawn in as it is bent up; it being understood that thehammer does not exert sufiicient force to stretch or expand the metal inthe direction of its width or length in the process of flattening whenthis is done, only a few blows being necessary to flatten the sheet.

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neonate Having thus described the invention, What is claimed as newis-- 1. Means for drawing-in operations on sheet metal includin a pairof cooperating dies having correlated facial contours adapt-- metalinclnding a pair of cooperating dies operating one upon another, one ofthe dies having a ridge and the other a relatively larger groove toloosely receive the ridge for creasing and condensing the metal, thedies having fiat faces for hammering down the creases, and means'forcontrolling the dies.

3. Drawing-in power hammer dies includ ing'a pair of dies having each anapproximately flat face, the face of one of the dies having aninclinedridge thereon, the face of the remaining one of the dies having a groovetherein that has an inclined bottom and is deeper than the height of theridge to freely receive the ridge and a layer of metal thereon,

4. Means for drawing-in portions of sheet metal including a stationarydie and a movable die, each die having an approximately flat face, oneof the dies having a ridge extending upward at an inclination from themiddle portion of the flat face, the remaining y flattening the creases,and means one of the dies having a groove extending from the middleportion of the flat face at an inclination thereto and adapted toloosely receive the ridge and a portion of the sheet metal thereon, tocrease and condense-the metal, the Hat faces being adapted to flattenthe creases.

5. The combination With a power hammer machine having an anvil and alsoa movable hammer body, of a pair of drawing-in dies secured respectivelyto the anvil and the hammer body, each of the dies having anapproximately flat central face portion, the edge portions of the facesbeing receding and curved, one of the dies having a ridge on one side ofthe central face portion, the top of the ridge extending at aninclination from the middle of the flat face portion, the remaining oneof the dies having a groove on one side of the central face portion, thebottom of the groove extending at an in clination from the middle of theflat face portion of the die, the groove being rela tively larger thanthe ridge to loosely receive the ridge. p

In testimony whereof we affix our signa' tures in presence of twoWitnesses;

U'llTU LIND@TR@M. TUlWU Mhlthlllh. Witnesses:

E, 'f, @novrns, M. f annnrralv,

